Crossed-beam study of the Al(2P1/2,3/2)+O2(X3Σg-)→AlO(X2Σ+)+O(3PJ) reaction at low and very low kinetic energies

The title reaction is revisited at kinetic energies between 255 and 6 meV with a new crossed-beam apparatus. The Al0 dissociation energy is evaluated to be D-o(AlO)= 5.27 +/- 0.01 eV. Al(P-2(1/2)) and Al(P-2(3/2)) spin-orbit reactivities are shown to be different. The relative cross-section of Al(P-2(1/2))+ O-2 is found to increase monotonically when decreasing kinetic energy. The variation of the calculated thermal rate constant is in agreement with kinetic measurements performed between 1083 and 23 K. Good agreement is also found with theoretical treatment based on the adiabatic capture centrifugal sudden approximation. (C) 1999 Elsevier Science B.V. All rights reserved.